file transfer script added

scripts/transfer.py

@@ -0,0 +1,62 @@
+import sys
+import serial
+import select
+import signal
+import time
+
+
+def print_usage():
+    print('Usage: python serialfile.py -in <serial device> > file', file=sys.stderr)
+    print('Usage: python serialfile.py -out <serial device> < file', file=sys.stderr)
+
+
+def get_serial(port: str) -> serial.Serial:
+    s = serial.Serial()
+    s.baudrate = 9600
+    s.parity = serial.PARITY_NONE
+    s.stopbits = serial.STOPBITS_ONE
+    s.bytesize = serial.EIGHTBITS
+    s.port = port
+    s.timeout = None
+    s.write_timeout = None
+    return s
+
+def data_ready_on_stdin():
+    return bool(select.select([sys.stdin], [], [], 0)[0])
+
+"""
+This utility receives/sends files via selected serial port to the
+Apple-1 Serial Interface card.
+
+This utility requires pyserial module to be installed:
+
+pip3 install pyserial
+"""
+if __name__ == "__main__":
+
+    if len(sys.argv) != 3:
+        print_usage()
+        exit(1)
+
+    if sys.argv[1] == '-in':
+        print('Press Ctrl+C after the transmission ends', file=sys.stderr)
+        
+        # terminate silently on SIGINT
+        signal.signal(signal.SIGINT, lambda s, fr: exit(0))
+        with get_serial(sys.argv[2]) as s:
+            while True:
+                sys.stdout.buffer.write(s.read())
+
+    elif sys.argv[1] == '-out':
+        # check if the data is available on stdin
+        if not data_ready_on_stdin():
+            exit(0)
+        with get_serial(sys.argv[2]) as s:
+            data = sys.stdin.buffer.read()
+            while len(data) > 0:
+                s.write(data)
+                data = sys.stdin.buffer.read()
+    else:
+        print(f'Unknown option: {sys.argv[1]}', file=sys.stderr)
+        print_usage()
+        exit(1)